1. Field of the Invention
The invention relates generally to a liquid crystal display (“LCD”) device, an LCD module and a backlight assembly of the LCD module.
2. Description of the Related Art
Conventionally, the LCD module has an LCD panel displaying images in response to electrical signals provided thereto, according to the change in arrangement of liquid crystal molecules and light transmittance, a backlight assembly supplying light to the LCD panel, and covers supporting and fixing the LCD panel and the backlight assembly. The LCD module is fixedly attached to a separate case, and provided to ultimate customers as the LCD device.
The LCD module is used in various kinds of display devices and classified into small-sized LCD modules for cellular phones, mid-sized LCD modules for desktop monitors, and large-sized LCD modules for television sets.
As the size of the LCD module increases, a weight of the LCD module also increases and its components and structure become more complicated in order to assure higher reliability such as shock-resistance and the like. Especially, the LCD module for use in either a desktop monitor or a television set may be provided with an additional light guide plate, a support supporting the light guide plate or the light source module, and a closed-type bottom container supporting the entire backlight assembly. The closed-type bottom container has a bottom section, and side walls upwardly extending from the bottom section, for isolating the light source module, the light guide plate and the light guide plate support from the exterior of the backlight assembly, thereby leading to an increased overall depth and weight of the LCD module.
The complicated structure in the closed-type bottom container for mounting circuit elements and connection to the LCD device results in an increased overall dimension of the LCD module. Even though the closed bottom container is made partially opened so as to mount some of circuit elements therewith, the general shape of the bottom container is still of a closed structure, so a reduction in thickness and weight of the LCD device and module are still required.
The backlight assembly included in the LCD module has a plurality of light sources. Each light source converts electrical energy to optical and thermal energy. Optical energy is desirable since it is delivered from the backlight assembly to the liquid crystal panel for displaying images, while thermal energy should be eliminated because of its negative influence to the liquid crystal molecules or other optical elements. However, since more light sources are required as the dimension of the liquid crystal module and device increases, and since a narrower thermal path is provided as the thickness of the liquid crystal module and device decreases, the image quality of the LCD module and device will deteriorate owing to excessive heat.
Accordingly, a structure for implementing more effective heat dissipation in the liquid crystal display module with a plurality of light sources is required. The LCD device includes the LCD module disposed between an upper case on the LCD panel side of the LCD module, and a lower case on the backlight assembly side of the LCD module. On the lower case is mounted an external device, by which the LCD device can be hung on a wall of a building or placed on a table. Here, it is appreciated that since the external device needs additional parts for mounting on the lower case, the LCD device tends to become larger and heavier. Moreover, such a larger dimension and weight of the LCD device may often decrease stability and reliability of the external device, so simplification of mounting structure of the LCD device is essentially required.
LCD device suppliers purchase individual LCD modules with a liquid crystal panel and a backlight assembly, and assemble them together with the upper and lower cases separately prepared, to manufacture a final LCD device. To the LCD device, an additional element that receives a combined image signal of a primitive image and sound signal, and splits the combined image signal into an image signal for LCD module and an acoustic signal for a speaker is installed. The LCD device is finally completed by the process of installing the additional element on the backside of the assembled LCD module, and combining the upper and lower cases with the LCD module in between. Here, since the lower case is combined with the upper case along an edge thereof, the sectional areas of both the lower and upper cases are similar to each other.
A thickness of the LCD device often becomes larger because LCD device manufacturers do not tend to seriously consider the location of the additional element disposed on the back of the LCD module, and design of the lower case with uniform depth for combining with the upper case. Further, even though the LCD device manufacturer makes a change in the depth of the lower case depending upon the location of the additional element, the lower case is combined with the upper case with constant interval between the cases throughout the LCD module; hence, limitation is caused in reducing the thickness of the LCD device. Still further, the manufacturing process becomes more complicated for those LCD device manufacturers as the lower cases becomes larger in some applications such as in a large sized television set. Accordingly, a structural improvement of the LCD module which promotes both easy and effective mounting of the additional elements to the LCD module, and the reduction in an overall size of the LCD device, is desired.